1. Field of the Invention
This invention relates to a chemical analysis system using a chemical analysis film which has a reagent layer whose optical density changes upon reaction with a specific biochemical component contained in a sample liquid such as blood or urine.
2. Description of the Prior Art
Quantitative or qualitative analysis of a specific component in a sample liquid is a common operation carried out in various industrial fields. Especially, quantitative analysis of a chemical component or a solid component contained in body fluid such as blood or urine is very important in the field of clinical biochemistry.
A chemical analysis system using a dry-type chemical analysis slide with which a specific component contained in a sample liquid can be quantified through a droplet of the sample liquid deposited on the slide is shown. See Japanese Patent Publication No. 53(1978)-21677, U.S. Pat. No. 3,992,158, Japanese Unexamined Patent Publication No. 55(1980)-164356, U.S. Pat. No. 4,292,272 for example. When such a dry-type chemical analysis slide is used, the sample liquid can be analyzed more easily and more quickly than when the conventional wet analysis method is used, and accordingly the dry-type chemical analysis slide is very convenient for medical facilities, laboratories and the like where lots of sample liquids have to be analyzed.
When chemical components or the like contained in a sample liquid are analyzed using such a dry-type chemical analysis slide, a droplet of the sample liquid is deposited on the slide and is held at a constant temperature for a predetermined time in an incubator so that coloring reaction occurs, and the optical density of the color formed by the coloring reaction is optically measured. That is, measuring light containing a wavelength which is pre-selected according to the combination of the component to be analyzed and the reagent contained in the reagent layer of the slide is projected onto the slide and the optical density of the slide is measured. Then the component to be analyzed is quantified on the basis of the optical density using a calibration curve which represents the relation between the concentration of the biochemical component and the optical density.
The chemical analysis slide generally comprises a chemical analysis film composed of a base film of plastic or the like and a reagent layer formed on the base film and a plastic frame which holds the chemical analysis film flat, the chemical analysis film being apt to warp into a roof tile shape when it dries.
Though the reagent in the reagent layer does not react without water, it can begin to react as soon as it absorbs moisture. Accordingly, in order to obtain precise result of analysis, it is most important to keep the reagent layer dry until it is used.
Further, in order to facilitate automation of the analysis, it is preferred that the chemical analysis slides can be smoothly fed one by one.
There has been known a cartridge in which a stack of a plurality of (e.g., fifty) chemical analysis slides is accommodated. (For example, see U.S. Pat. Nos. 4,151,931, 4,187,077, 4,190,420 and 4,279,861.)
In the cartridge, each time the uppermost slide in the stack is pushed laterally out of the cartridge, a lift member is inserted into the cartridge below the lowermost slide and the stack of the slides is lifted upward by the distance corresponding to the thickness of one slide. Such an operation is repeated until all the slides in the cartridge are taken out.
Since a large number of chemical analysis slides are used in a short time, the cartridge must be large in size. Moreover, a plurality, equal to the number of the biochemical components to be analyzed, of the cartridges must be provided in the analysis system, which results in increase in the size of the system.
Further, in such a chemical analysis slide, the frame is so expensive that the cost of biochemical analysis increases.